DAV Class 7 Science Chapter 9 Reproduction in Plants Question Answer Notes
DAV Class 7 Science Chapter 9 Reproduction in Plants Question Answer Notes Solution by Expert Science Teacher. DAV Class 7 Science 9th Chapter Reproduction in Plants for Students of DAV Schools.
Lesson No 9
Reproduction in Plants
A.) Fill in the blanks.
Answer: (1) Yeast (2) anther (3) pollinators (4) fertilisation (5) wind
B.) Write True or False for the following statements.
Answer: (1) False , it reproduces asexually through spore formation(2) True (3) False, bisexual flower have both stamen and pistil (4) True (5) True (6) True
C.) Tick the correct option.
Answer:
1.) fragmentation
2.) leaves
3.) flower
4.) male reproductive cell
5.) ovary
D.) Answer the following questions in brief.
Q.) 1.) Name the two types of reproduction in plants.
Answer: Two types of reproduction in plants are:
(1) Asexual reproduction
(2) Sexual reproduction
Q.) 2.) Define vegetative reproduction.
It is the process of asexual reproduction in which parts of the parent Organism is utilized to create a new individual.
Q.) 3.) Give two examples of plants which reproduce through spore formation.
Answer: mosses and ferns
Q.) 4.) Name two artificial methods of vegetative propagation from stem.
Answer: Grafting and Layering
Q.) 5.) When is a flower said to be a bisexual flower?
Answer: Bisexual flowers are those that have both male and female reproductive organs. This shows that the flower has both male and female reproductive organs and may self-pollinate. Bisexual flowers are sometimes known as hermaphroditic blooms. The most well-known type of bisexual flower is the perfect flower, which possesses both male and female reproductive organs and is capable of self-pollination. Beautiful flowers include many members of the rose family, such as apples and roses, as well as many orchid species.
Q.) 6.) Name any three ways by which seeds are dispersed
Wind dispersal is the process through which the wind blows the seeds away from the originating plant. Certain plants have developed to take advantage of this method of seed dissemination.
Seeds that are distributed by water float downstream on a river or ocean current.
Animal Dispersal: This process occurs when animals consume the seeds and then afterwards release them in a new location.
E.) Answer the following questions.
Q.) 1.) In what ways is vegetative propagation better than sexual reproduction?
Vegetative propagation offers a variety of advantages over sexual reproduction. First, vegetative propagation eliminates the need for pollination, which in some regions can be costly, time-consuming, and unreliable. Additionally, vegetative propagation ensures that the offspring will be genetically similar to their parent plant, in contrast to sexual reproduction, which might lead to the offspring having genetic makeups that are drastically different. This increases the likelihood of positive traits being passed down.
Q.) 2.) Draw a well labelled diagram to describe the parts of a flower.
Q.) 3.) How is self pollination different from cross pollination?
Answer: Self-pollination is the process by which male and female reproductive elements (pollen and eggs) from the same flower or plant combine to produce a seed. Self-pollination frequently occurs within a single blossom or among two flowers on the same plant. It is naturally traversed by a variety of plant types, including flowers, grasses, and trees. On the other hand, cross-pollination takes place when pollen from one bloom is transferred to the female reproductive system of another flower within the same species. Usually, insects, birds, and wind perform this function. It encourages genetic variability within the species by allowing different plants to exchange their genetic information.
Q.) 4.) How are fruits formed?
Answer: Fruits are produced by the process of pollination. The transfer of pollen from a flower’s male (stamen) to female (stamen) components is known as pollination (the pistil). The pollen grains contain the sperm cells, whilst the pistil contains the female gametes (egg cells). When pollen grains come into touch with the pistil, male gametes (sperm cells) travel down the pistil to the ovules (egg cells) located at its base. Fertilization occurs when the male and female gametes mix to form a zygote. A fruit is produced after the zygote changes into a seed.
Q.) 5.) Why is dispersal of seeds necessary for growth of plants?
Answer: The spread of seeds is essential for plant growth. When seeds are dispersed, they are exposed to new environments that may provide perfect conditions for their successful germination and growth. Plants can colonise new areas thanks to dispersal, which helps keep the species alive. By scattering, plants can get away from challenging conditions like contending with other plants or harsh weather. By dispersing their pollen to environments that are more favourable to their growth, plants can prevent environmental conditions that may be harmful to their development. For plants that cannot tolerate drought or exceedingly high temperatures, this is essential.
More Extra Questions for Preparation
Q.1.) Fill in the blanks.
1.) Roots, stems and leaves are known as vegetative part of plant.
2.) Yeast reproduce asexually through budding.
3.) Petals help to attract insects for pollination.
4.) Apples are termed as false fruits.
5.) Urena have spiny seeds with hooks.
Q.2.) Why apple’s are called as false fruits?
Answer – Apple is known as false fruits as the juicy edible portion does not develop from the ovaries but from the receptacle present above the stalk of flower.
Q.3. Define.
1.) Pollination.
Answer – Transfer of pollen grain from the anther to stigma in flowers is known as pollination.
2.) Fertilisation.
Answer – Fertilisation is the process of male and female gametes.
Q.4.) Choose the correct answer.
1.) Can be multiplied by breaking part from old stem and growing it in soil.
a.) Tulip
b.) Cacti
c.) Rose
d.) Aloevera
Answer – b. Cacti
2.) Bryophyllum is also known as .
a.) Mother of thousands
b.) Father of hundreds
c.) King of all
d.) None of these
Answer – a.) Mother of thousands
3.) Protects the inner part of flower
a.) Stamen
b.) Sepals
c.) Petals
d.) Carpel
Answer – b.) Sepals
4.) is unisexual flower.
a.) Tomato
b.) Mustard
c.) Brinjal
d.) Papaya
Answer – d. Papaya
5.) reproductive part consisting of ovary and ovules.
a.) Pistil
b.) Sepal
c.) Petal
d.) Carpel
Answer – a.) Pistil
Q.5.) Answer the following.
1.) Explain the ways of seed dispersal.
Answer – a.) Dispersal by wind
b.) Dispersal by animals
c.) Dispersal by water
d.) Dispersal by explosion of fruit.
2.) What are pollinators?
Answer – Pollinators are agents that carry or transfer the pollen grains from an anther to a stigma.
3.) Explain parts of flower.
Answer –Flower have sepals, petals, stamens and pistils.
A.) Sepals– Form’s outermost whorl of green leaf like structure. Protects inner parts of the flower.
B.) Petals– Are bright red coloured and also produces fragrance. It helps to attract insects for pollination.
C.) Stamen– It is a male reproductive part. It consists of anther and filament.
D.) Pistil– It is a female reproductive part. It consists of ovary and ovules.
4.) Explain development of seed.
Answer – The ovules form seeds. A seed has cotyledons to store food and the future plant that is embryo.
5.) Explain fragmentation in Spirogyra.
Answer – 1.) A Spirogyra reproduces asexually by process of fragmentation.
2.) A Spirogyra filaments break into two or more fragments.
3.) These fragments grow and develop into new individual.
4.) As this process continues, the whole pond may get covered by green scum.
Q.6.) Explain process of fertilization.
Answer – a.) Pollen grains germinate when they fall on the stigma of a flower of the same species.
b.) A pollen tube is produced that reaches the ovule.
c.) The male and female reproductive cells are called gametes.
d.) This process of fusion of the male and female gametes is called fertilization.
Q.7.) What is ripened ovary?
Answer – After fertilization, the ovary begins to grow and forms the fruit.The fruit may be sweet and
juicy or they may be hard and woody. The fruit is thus actually a ripened ovary.
Q.8.) Name the following.
1.) Example of non flowering plants.
Answer – Mosses and ferns
2.) Yeast used as probiotic.
Answer – Saccharomyces bauldardii
3.) Types of reproduction in plants.
Answer – a. Sexual reproduction
b.) Bisexual reproduction
4.) Name any one algae.
Answer – Spirogyra
5.) Eye like structure called.
Answer – Buds
6.) Artificial method of vegetative propagation.
Answer – Grafting and layering
7.) Types of pollination.
Answer – Self pollination and Cross pollination
8.) Fruits which are carried away by water.
Answer – Lotus, water lily and coconut palm.